The present invention relates to a production method of chemical reactive substances, polycarboxylic acids produced thereby as well as cement additives, dispersants, builders for powder detergents and builders for liquid detergents.
A production method of chemical reactive substances which comprises reacting a liquid material containing reactive substances having unsaturated double bonds is used for production of polymers by polymerization reaction of unsaturated double bonds, and for production of chemical reactive substances having unsaturated double bonds that can be used as materials for production of polymers, and is applied in various industrial fields as a production method of industrially useful chemical products. For example, it is used in order to produce cement additives (cement dispersants), builders for powder detergents, builders for liquid detergents, dispersants, for example, pigment dispersants for dispersing calcium carbonate, carbon black and ink, scale inhibitors, dispersants for gypsum and water slurries, dispersants for coal-water slurries (CWM), thickeners, and other chemical products.
In order to produce substances industrially efficient and with large quantities using such a production method, for example, chemical reactive substances are produced by injecting a liquid material containing reactive materials having unsaturated double bonds into a reaction vessel through a material injection nozzle of the reaction vessel, and effecting the reaction. However, when starting materials, such as a liquid material containing reactive materials having unsaturated bonds, are supplied into said reaction vessel through the material injection nozzle of the reaction vessel, there has been a problem such that starting materials remained in the material injection nozzle, thereby the solidified matter and/or gelled matter may block the material injection nozzle, or the gelled matter may be contaminated into the reaction system.
If the material injection nozzle is blocked by the gelled matter, feeding of starting materials into the reaction vessel becomes impossible, and production cannot be carried out appropriately, as well as such a problem that the gelled matter formed is contaminated into the reaction system may occur. Moreover, if the gelled matter is contaminated into the reaction system, it becomes difficult to produce chemical reactive substances with stable quality. Further, blockage due to the gelled matter will cause a trouble of production facilities, such as pump stop, in a transfer step of produced chemical reactive substances and a feeding step, whereby stable production is disturbed. Therefore, the device is needed for industrially stable production of chemical reactive substances with excellent quality using liquid materials containing reactive substances having unsaturated double bonds.
In view of the above-mentioned state of the art, an object of the present invention is to provide a production method of chemical reactive substances with stable quality by which solidification, gel formation, and the resulting blockade within material injection nozzles are prevented, and contamination of a reaction system with the gelled matter is prevented, as well as occurrence of problems on a production process due to the gelled matter is suppressed, when the chemical reactive substances are produced by injecting the liquid materials containing reactive substances having unsaturated double bonds into the reaction vessel through the material injection nozzles of the reaction vessel.
The present inventors made the investigation on a production method of chemical reactive substances which comprises injecting liquid materials containing reactive substances having unsaturated double bonds into a reaction vessel through material injection nozzles and first noticed that gelled matters are formed from starting materials remained in the material injection nozzles (1) when a reaction is carried out at reaction temperature of not less than 50xc2x0 C. using liquid materials containing reactive substances having unsaturated double bonds, (2) when liquid materials containing polyalkylene glycol monomers (I) and carboxylic acid monomers (II) are used, (3) when liquid materials containing carboxylic acid monomers (II) are used, and (4) when liquid materials containing a carboxylic acid monomers (II) and polyalkylene glycol (III) are used. Moreover, they also noticed that the gelled matters block the material injection nozzles, and are contaminated into a reaction system, and, as a result, quality of products is deteriorated or problems are occurred in the production process. In such cases, they found out that the above-mentioned problems can be solved by including a step of removing at least a part of residual liquid remained in the material injection nozzles from the inside of the material injection nozzles. Further, they found out that, when the substance removed from inside of the material injection nozzles in such a step is a polyalkylene glycol (III), effects of the present invention are suitably manifested. Furthermore, they also found out that the formation of the gelled matter within the material injection nozzles is efficiently prevented when at least a part of residual liquid in the material injection nozzles is purged and extruded from the material injection nozzles using one or two or more of gaseous substances, water and starting materials charged other than the material concerned injected through the material injection nozzles. Therefore, they found out that the above-mentioned production method is effective in order to produce industrially useful chemical products with stable quality, that the production method is especially effective when applied for production of polycarboxylic acids and the polycarboxylic acids are applied in cement additives, dispersants, builders for powder or liquid detergents, and thus the present invention is accomplished.
Accordingly, the present invention is a production method of a chemical reactive substance
which comprises injecting a liquid material containing a reactive substance having an unsaturated double bond into a reaction vessel through a material injection nozzle of said reaction vessel and causing a reaction at a reaction temperature of not less than 50xc2x0 C.,
said production method of the chemical reactive substance including a step of removing at least a part of residual liquid remained in the material injection nozzle from inside of the material injection nozzle.
The present invention is also a production method of a chemical reactive substance containing a polycarboxylic acid
which comprises carrying out copolymerization of a liquid material containing a polyalkylene glycol monomer (I) and a carboxylic acid monomer (II) in a reaction vessel,
said polyalkyleneglycol monomer (I) and said carboxylic acid monomer (II) being injected, individually or as a mixed solution, into the reaction vessel through a material injection nozzle of said reaction vessel, and
said production method of the chemical reactive substance including a step of removing at least a part of residual liquid remained in the material injection nozzle from inside of the material injection nozzle.
The present invention is also a production method of a chemical reactive substance containing a polycarboxylic acid
which comprises carrying out polymerization of a liquid material containing a carboxylic acid monomer (II) in a reaction vessel,
said carboxylic acid monomer (II) being injected into the reaction vessel through a material injection nozzle of said reaction vessel, and
said production method of the chemical reactive substance including a step of removing at least a part of residual liquid remained in the material injection nozzle from inside of the material injection nozzle.
Further, the present invention is directed to a production method of a chemical reactive substance containing a polyalkylene glycol monomer (I)
which comprises carrying out esterification of a liquid material containing a carboxylic acid monomer (II) and a polyalkylene glycol (III) in a reaction vessel,
said carboxylic acid monomer (II) and said polyalkylene glycol (III) being injected, individually or as a mixed solution, into the reaction vessel through a material injection nozzle of said reaction vessel, and
said production method of the chemical reactive substance including a step of removing at least a part of residual liquid remained in the material injection nozzle from inside of the material injection nozzle.
Further, the present invention is a polycarboxylic acid obtainable by copolymerizing a liquid material containing a polyalkylene glycol monomer (I) and a carboxylic acid monomer (II),
which is produced by said production method of a chemical reactive substance.
The present invention is also a polycarboxylic acid obtainable by polymerizing a liquid material containing a carboxylic acid monomer (II),
which is produced by said production method of a chemical reactive substance.
The present invention is also a cement additive comprising said polycarboxylic acid.
The present invention is also directed to a dispersant comprising said polycarboxylic acid.
The present invention is further a builder for a powder detergent comprising said polycarboxylic acid.
Finally, the present invention is a builder for a liquid detergent comprising said polycarboxylic acid.